Grinding machine



Dern 1, 1942.

c. HERFURTH Erm. 2,303,639v

GRINDING MACHINE Original Filed April 25, 1938 l 3 Sheets-Sheet 1 ATTORNEY.

Dec. l, 1942. HERFURTH ErAL 2,303,639

GRINDING MACHINE original Filed Aprii 25, 193s s sheets-sheet 2 INVENI ORS.

' ATTORNEY.

. 1, 1942.l c. vl-uzRFuRTl-l x-:rAL

5 Sheets-Sheet 3 ATTORNEY.

Patented Dec. 1, 1942 UNITED STATES PATENT OFFICE GRIND'ING MACHINE Charles Herfurth and` Raymond D. Wortendyke, Cincinnati, Ohio, assignors to Cincinnati Grinders Incorporated, Cincinnati, Ohio, a corporation of Ohio Original application April 25, 1938, Serial No. 204,083, now Patent No. 2,254,010, dated August 26, 1941. Divided and this application December 30, 1940, Serial No. 372,240

11 Claims. (Cl. 121-45) This invention relates to improvements in Ways for traversing movement relative to a grinding machines and more particularly to imgrinding Wheel I4. provements in the` transmission and control As shown in Figure 1, the grinding Wheel I4 mechanism therefor, and is a division of copendmay be supported on a spindle I 5 for rotation ing application Serial No. 204,083, led April 25, 5 by a motor I5. The grinding Wheel and motor 1938, issued as Patent No. 2,254,010. are mounted on a subslide I'I which is movable One of the principal objects of the present inrelative to a support I8, which in turnis pivoted vention is the provision of an improved actuating for movement about an aXis I9 located under mechanism for a machine of this character which the grinding Wheeir will effect a smooth and uniform relative shift- 10 Suitable mechanism may be emplOYed for ing of the parts of the machine and shoekless eiecting movement ofthe slide I1, but since this reversal of the direction of their relative movemechanism OIInS n0 part 0f the present inVenment. tion, it has not been illustrated.

A further object of the present invention is Referring to Figures 2 and 3, the mechanism the provision in a transmission of this character OI iIeVeISing the table comprises a rotary hyof controllable means for independent determidraulic motor which is operatively Connected nation of the rates of deceleration and accelerato a" dIiVe Shaft 2| for rotating a Worin 22 entition in connection with reversal or change of fIiCiiiOneliY Supported in the bed. This WOIIn direction of relative movement of the parts, meshes With a Worm Wheel 23 secured to the lower Another object of the invention is the provision 20 end of shaft 24 which is also antifrictionally supof a novel control mechanism for effecting the ported in the bed- The Upper endl of this Shaft changes of rate and direction of movement of has anvin'eglal pinion 25 meshing With a raek the parts. bar 26 secured to the under side of the table Other objects and advantages of the present between the guideways Il and l2. It Will 110W invention should be readily apparent by reference be apparent that upon rotation of the hydraulic to thev following specification, considered in conmotor in one direction or the other that the table junction with the accompanying drawings formmay be traversed relative to the grinding Wheel. ing a part thereof and it is to be understood that The ieiioie i 3 hes e headsiook 27, and a teilany modifications may be made in the exact stock 28, mounted thereon for adjustment'to structural details there shown and described, aoeominodeie diereniengthS 0f WOIk PieCeS. within the scope of the appended claims, without The axis 29 which connects the points of the departing from or exceeding the spirit of the Work Supporting Centers 30Yand 3| may be defined invention. as the rotational axis of the Work. This machine Referring to the drawings in which like refis especially suitable for grinding rolls and vis erence numerals indicate like or similar parts: Provided With -n adjustable @amber Control Figure 1 represents a transverse sectional view mechanism Which operates to oSCilieie the 511D- Of the machine Constructed in accordance with DOI' i8 abOll theaXlS I9. Since this aXS S under and embodying the principles of the invention, the grinding Wheel, the lever arm which connects Figui-e 2 presents a diagrammatic View of the this axis to the center 32 of the grinding Wheel essential parts of the machine and the hydraulic 40 mOi/es Practlcally at right angl@ t0 a line 33 control circuits therefor, the controlling valve Whlch Connects Phe, ams of Totatlon 29 to the elements being indicated in Section, and center of the grinding Wheel so that for small Figure 3 represents a diagrammatic view of the glrgnoelsnbghl tsllgsg arg1-,radiatesgagnerait? e ma be more toward and from the Work along substantially the controls for the hydraulic c1rcu1t. a radial une thereof Flgure 4 p11 esents a new of. a detal 0f one of 'I'he mechanism for oscillating the support I8 the Valve qevls 0f the mammeto produce the cambering action consists'of a A machine embodying the principles of this oamber control mechanism which is driven from invention iS Shown in Figure l 0f 1She drawings, the table rack 26 througha synchronized transand in general COmloTiSeS a bed l0 Upon the top mission which maintains the Vcamber control 0f Which are formed guideways II and I2 as mechanism in exact step with the movement of more particularly shown in Figure l. A Work the table. The adjustable camber control vmechsupporting table I3 is mounted on these guide- 55 anism to be described does not constitute part of the present invention, but is described and claimed in a separate copending application, Serial Number 204,082, filed April 25, 1938, issued as Patent No. 2,167,948. The rack 20 engages a pinion 34 which is keyed to the upper end of the shaft 35. This shaft is connected through a bevel pinion 36 and a bevel gear 31 to a longitudinal shaft 38. This shaft has a splined end 39 fitting 31 so as to facilitate assembly of the parts. The shaft 30 has a spur gear 44 keyed to the end thereof and intermeshing with a gear 45 keyed to a stub shaft 40.

The gears 44 and 45 are removable and gears of different sizes may be substituted therefor whereby they constitute change gears for varying the rate of actuation of the-remainder of the gear train.

The shaft 4S also has a gear 48 which intermeshes with a large gear 49. The gear 49 is supported by a shaft 5|.

Means have been provided for taking the backlash or lost motion out of the drive connection for the table, and this means or mechanism acts in such a manner that the backlash is always taken out in one direction only and regardless of the direction of movement of the table. This is necessary in order to prevent shifting of the maximum point of camber relative to the work.

The mechanism for accomplishing this comprises an hydraulic motor |09. The drive shaft of this motor is provided with a spur gear I I I, which is connected by the double gear I I2 to the gear 49. It will now be apparent that when the shaft 33 is rotated to cause actuation of the gear 49, that the gear 49 in turn will drive or tend to drive the gear III on the end of the motor shaft I|0. In order that the backlash may always be taken up in one direction regardless of the direction of movement of the table, or, in other words, the direction of rotation of the shaft 38, means have been provided whereby the pressure in the motor |09 may be varied so that during rotation of the shaft 30 in one direction, the motor will act as a retarding or braking means, and during rotation of the shaft 30 in the other direction, the pressure in the motor will be increased so that the motor will serve as a driving means.

Although the motor |09 would otherwise be able to do the driving and feed the table, it must be remembered that the feed motor 20 is connected to the table through a worm and worm gear drive and therefore the actual rate of movement of the table will still be determined by the feed motor so that the motor |09 although actually moving the table will do so at a rate determined by the rate of rotation of the feed motor 20.

This change in the unidirectional pressure acting on the motor |09 is automatically effected when the work supporting table is reversed and is effected by the reversing 'mechanism The two different pressures needed for the operation of motor |09 are provided by the pump |04, and a selector valve |I3 is provided for alternately connecting these pressures to the motor. The higher pressure is provided by connecting the output of pump |04 directly to port ||4 of the selector valve. obtained by connecting a branch line ||5 in series with a pair of relief valves IIB and ||1. The valve I I6 is set to yield the higher pressure in channel |03, and cause a pressure drop in the iiuid owing to channel H8. This channel is The lower pressure is `in a splined bore 40 integral with the bevel gear connected to the relief valve ||1 which is set at a lower pressure, and channel ||8 is connected to port ||9 of Valve |I3 so that this predetermined lower pressure may be connected to the motor |00.

The two relief valves act as hydraulic resistances for determining an intermediate pressure in the channel ||8, the valve IIS serving as a resistance in, and the valve ||1 serving as a resistance out The selector valve ||3 has a port |20 which is connected by a channel I2I to port |22 of a cut out valve |23 for the motor |09. This valve has a plunger |24 in which is formed an annular groove |25 which, in the position shown, serves to connect the port |22 to port |26. The port |26 is permanently connected to port |21 of valve 91. The valve plunger 96 has an annular groove |28, which is in such a position, when the door of the gear box is closed, to interconnect port |21 to port |29 and thereby to channel |30 which leads to the hydraulic motor |09. The other port of the motor is permanently connected through channel |3I to the reservoir |00. Whenever the valve plunger |24 is pulled out, a spool |32 closes the pressure port |22 and the annular groove |25 interconnects port |20 to an exhaust port |33. Thus when the gear box is closed, and the valve plunger |24 is pulled out, both ports of the motor |00 are connected to reservoir, thereby offering no resistance or braking action on the table drive mechanism. When the valve plunger |24 is in the position `shown in Figure 3, and the gear box cover is opened, the shifting of valve plunger 90 will disconnect port |26 from port |29, and the annular groove |28 will interconnect the port |29 to the exhaust vchannel |34 whereby the pressure will be off of the motor |09, so that the gear 49 may be rotated readily for set-up purposes.

When the valve plungers 96 and |24 are vin the position shown in Figure 3, the selection of pressure delivered to the motor |09 is determined by the selector valve ||3 and to this end the valve has a plunger |35 in which is formed two annular grooves |36 and |31. When the plunger |35 is shifted to the left, the annular groove |31 interconnects the lower pressure port I I9 to port |20, and when the plunger is shifted to the right, the annular groove |36 interconnects the higher pressure port |4 to port |20.

The plunger |35 is shifted automatically in accordance with the direction of movement of the table, and the ends of the valve housing ||3 are provided with ports |38 and |39 which are connected respectively through channels |40 and I4! to a pilot valve |42, shown in Figure 2. The pilot valve |42 has pressure ports |43 which are connected by a channel |44 to a suitable source of operating pressure; and ports |45 and I 46 on opposite sides thereof to which are connected the channels |4| and |40 respectively.

.The valve plunger |41 is self-actuating in that it has a central spool |40 which is larger in diameter than the two end spools |40 and |50. When the plunger is to the left, the annular groove |5| interconnects pressure port |43 to port |40 to cause shifting of the plunger |35 to the right. A trip operable mechanism is provided for shifting the plunger |41, but it will be noted that after the plunger passes the pressure port |03 in either direction, the pressure differential created by the difference in area between the spool |40 and the end spools will complete the shifting movement thereby simulating the action of a conventional detent mechanism.

The trip mechanism comprises a trip plunger |53 from which projects a pair of wings |54 and |55, the Wings lying in dilerent planes, as shown in Figure 1. 'Ihese wings are alternately engaged by dogs |56 and |51 carried by the table I3 for rotating thev plunger. t The plunger has a ball-ended lever |58 which engages a groove |59 formed in the valve plunger |41 for shifting the same. It will thus be evident that the direction of movement of the table determines the position of the selector valve plunger and thereby the value of the unidirectional pressure to be applied to the motor |09.

'I'he trip plunger not only determines-the pressure to be applied to the backlash motor, but also controls the reversing ofl the feed motor 20, and in such a manner as to cause deceleration of the motor at' a uniform rate prior to the shifting of the reverse control valve. The entire cycle of reversing, however, includes not only the deceleration of the table, but also means for eiecting a predetermined dwell of the table, and a controlled uniform acceleration in the opposite direction. This manner of reversing the table eliminates any sudden changes in rate which might cause undesirable vibrations and their resultant eiTect upon the finish of the work. These various results are obtained by a reversing control valve |80, which has an acceleration and deceleration control valve plunger ISI, and a reversing control sleeve |62. 'I'he -plunger A IBI is Vconnected by a ball ended crank |63 to the trip plunger |53 for actuation thereby.

The reversing valve has a pair of motor ports |64 and |65, which are connected by channels |66 and |61 respectively to ports |68 and |69 of a start-and-stop control valve |10. This valve has a plunger |1I which, when in the running' position shown, interconnects ports |69 and |68 to ports |12 and |13 and thereby through channels |14 and |15 to the motor 20.

The valve |60 also has a pair of pressure ports |16 and |11 which are supplied through a 'channel |18 from port |19 of a rate control valve indicated generally by the reference numeral |80. The valve also has a pairof .exhaust ports |8| and |82 which are connected to the return channel |83. The reversing valve sleeve |62 has a series of annular grooves |84, |85, |86, |81, |88,

and |89 which are in continuous communication with ports |8|,'|64, |16, |11, |65, and |82 respectively. Each ofA these annular grooves has a series of radial holes drilled in thek bottom thereof and communicating withthe interior of` the sleeve, thus forming portsfor control bythe inner plunger.

In the position of the parts shown in Figure 2. the table I3 has been moved toward the. left and the beveled face |90 on the dog |51 has en-` gaged the curved face |9| on the wing |55 and rotated the plunger |53 in a' counterclockwise direction, and this rotation has' takenplace through a predetermined length of movementI of the table. This means that the plunger 6|,

which wasv in a right hand position interconnecting pressure port |16 to motor 'port |64, and motor port |65 to exhaust port |92, wasV moved toward the left at a predetermined rate togradually close port |16 and thereby throttle the flow to the motor 20 to effect deceleration thereof. After the trip plunger rotated through half v of its angle of movement,'the automatic self actuation of the pilot` valve quickly completes the movement. Thisresults in deceleration Vand nal stoppage of the motor v20 `and thereby of the table I3 by trip eiected positioning of member |6| which acts as a stop valve counteractible by subsequent shifting of the enclosing reversing vvalve sleeve |62.

The final shifting of the pilot valve caused admission of pressure to port Mii-'and thereby to branch channel |92 leading to port |93 located in the left hand end ofvalve housing |60. This Yresulted in pressure being admitted to cause shifting of the reversing sleeve |82- The space |94 in the other end of the valvehousing is in com munication through an interdrilled passage |95 in the sleeve. to port |96 and this port is connected by channel |91 to ports |98 and' |99 of a combinationtarry and acceleration control valve 200. The fluid entering port |99 of this valve passes through a spring closed check valve 20| to an interdrilled passage 202 which terminat/es in an annular groove 203 formed in the tarry control valve plunger 204. V

A spoo1'205 on one` side of this groove has a 'series of Vshaped grooves 206 formed in its periphery which control the rate of now to a port lThe port 201 is connected by channel 208 to port |45 of the pilot valve |42, and at this time this port is connected'to the return channel I 83. Thus the ratev of movement of the sleeve |62'toward the'right depends upon the setting of the tarry control valve `plunger 204. This will determine the length of tarry of the table, which will continue until the sleeve |62 is shifted toward the right `a suillcient` distance to interconnect thepressure port |11 with the motor-port |65. y

At this point in the cycle'of movement of the sleeve toward the right, the port |96 will close and a second port 209 will just start to open. In other Words, the end of the sleeve is provided with a second interdrilled passage 2|0 which will now bel placed in communication with the port 209. This means that-the fluid that is Vbeing exhausted from the space' |94'Will stop llowing'through port |96 and will vstart to ow through port- 209 and f channel 2|| topo'rt 2| 2 of a combination tarry and `acceleration control valve indicated generally'by the reference numeral 2| 3.y This port communicates with a T-shaped interdrilled passage 2| 4whichterminates ina spring pressed ball 'check valve 2|5. The `uid ows past this check valve into a spiral groove 2|6 which has suiciently small pitch to offerl a definite resistance to the flow of fluid" through it.

This spiral Vgroove terminates in a port 2|1 which is connected by channel 2|8 to channel 208 leading to port |45 of the-pilot valve |42. The

port is connected 'atlthis time to an exhaust for determining the ratevof the last part of the stroke of the reversing valve sleeve to determine the rate4 of acceleration lof the table in the new direction. 1

iAfter thepressu-re port |11 has become fully 'connected to port |65, the rate of lluid supply to the motor 20is'vdetermined by the rate control .valve |80. The'supplyof operating fluid for `the motor 20 comes from a separate pump 220 through channel 22| to port 222 of a combining valve 223. This valve has a straight passage 224 through it, which terminates in port 225 that is connected by channel 225 to port 221 of the rate control valve |80.

The rate valve has an adjustable plunger 228 which is urged in one direction by a spring 229 to close port 221, and in the other direction by a separate plunger 230 which is` threaded in the bed of the machine. The plunger has a series of longitudinally extending V-shaped grooves 23| which decrease in depth at one end so that as the plunger 228 is moved against the resistance of spring 229, the resistance of port 221 may be gradually reduced. In this manner the flow of uid to the hydraulic motor 20 is throttled to yield various feed rates.

When the rate valve is adjusted to a position to yield the higher feed rates, the pump 220 will not deliver sufcient volume to produce these rates, and therefore an auxiliary pump has been provided together with suitable control means for automatically combining or adding the delivery of the auxiliary pump to that of the main pump. In order, however, to prevent the auxiliary pump from laboring when not being utilized, a by-pass connection has been provided and this by-pass control is so arranged that the discharge from the auxiliary pump is gradually throttled as the setting of the rate valve goes up, so that desirable division of flow of the output of the auxiliary pump is made in accordance with the demands for extra fluid and in accordance with the degree of increase in the rate.

As shown in Figure 2, the auxiliary pump 232 is connected by a channel 233 to port 234 of the combining valve 223. The port 234 is normally maintained closed by a spring pressed plunger 235 and the spring is assisted by the pressure existing in channel 226, there being a branch connection 236 from this channel to the end of the bore 231 which contains the plunger. The pressure that will exist in the channel 233 tending to shift the valve plunger 235, will depend upon the setting of an auxiliary valve plunger 233 which is mounted in the same block with the rate valve and adjusted by the same control. This valve has a port 239 to which a branch 240 of channel 233 is connected, and when the rate valve is set for low feed rates, the port 239 is connected to a reservoir port 24| by means of an annular groove 242 formed in the plunger 238.

When the plunger 230 of the rate valve is adjusted in a direction to increase the feed rate, a laterally extending arm 243 which is connected to the plunger 238 moves this plunger simultaneously with plunger 228 and in a direction to gradually close the port 242 and thereby increase the pressure in channel 240 to such a point that when the pressure in the channel 224 drops below a predetermined minimum, the valve 235 will open and thereby combine the delivery of the auxiliary pump with that of the main pump.

Automatic reciprocation of the table is stopped by shifting the plunger |1| of the start and stop control valve downward, as viewed in Figure 2, by rotating the control handle 244 to a central position. This will close ports |69 and |68, thereby stopping the flow to and from the motor.

When the table |3 moves toward the right, as viewed in Figure 2, the inclined surface 295 on the dog |56 engages the wing |54 of trip plunger |53 rotating the same in a clockwise direction, thereby shifting the pilot valve control plunger to the right and. simultaneously moving the .deceleration control valve plunger |6| in the same direction. The result is the gradual closing of pressure port |11, whereby the rate of movement of the table will decrease.

The fluid pressure that is admitted to port |45 by the shifting of the pilot valve will flow through channel 208 to port 296 of control valve 2|3. This valve has a throttle valve plunger 291 similar to valve plunger 205 which throttles the ow from port 296 into the annular groove 29S. The fluid continues through an interdrilled passage 299 and past spring closed check valve 300 to channel 2|| through which it continues to the right hand end of valve |60. This will cause movement of the sleeve |62 toward the left until the port 209 closes. A

Since the uid can no longer flow through valve 2|3 from channel 200 on accountof the closing of port 209, it will be forced through port 30| and spiral groove 302 of valve 209,.to the interdrilled passage 303, which terminates in a spring closed check valve 304. This valve will open, and the uid will continue through port |98 and channel |91 to port |96of valve |60, thereby continuing the movement of the sleeve |62 to the left andl causing the motor to accelcrate in the new direction. It is thus possible to cause the table to decelerate to a stop, tarry, and accelerate in a new direction at each end of the table stroke.

What is claimed is:v

1. In a machine tool having a reciprocating support, the combination of a hydraulic control circuit for said support, including a fluid operable motor, a source of pressure, a valve interposed between said source of pressure and said motor including telescoping members, an actuator operatively connected for moving one of said members in a direction to reduce the flow of fluid to said motor, fluid operable means for shifting the second of said members, and a control valve operatively connected to said actuator for subsequently effecting the admission of shifting pressure to said iiuid operable means to effect reversal of said motor.

2. In a grinding machine having a reciprocable support, the combination of a hydraulic motor for effecting said reciprocation, a control circuit for said motor, including a decelerating valve and a reversing valve, a rotatable trip plunger, means connecting said plunger to the decelerating valve, a pilot valve for controlling the hydraulic shifting of the reversing valve, said pilot valve being connected to said trip plunger, and dog means carried by the table for oscillating said plunger whereby said table will be decelerated and then reversed.

3. In a machine tool having relatively movable tool and work supports and a iluid operable motor for controlling reciprocation of one of said supports relative to the other, the combination of a hydraulic control circuit for said motor, including a valve housing having telescoping decelerator and reversing valve members, mechani- 'cal means operable by the table for shifting said decelerator valve, cylinders formed on the ends of said valve housing, piston portions on the end of said reversing valve member reciprocable within said cylinder portions, means operable by the moving support for admitting fluid pressure to one of said cylinders, means t0 control the exhaust from the other cylinder, including an adjustable throttlevalve, a hydraulic resistance,

and means responsive to a partial movement of the decelerator valve member for disconnecting the exhaust from said throttle valve and connecting it to said hydraulic resistance.

i 4. In a machine tool having relatively movable tool and Work supports, the combination of a hydraulic motor for controlling reciprocation of one of said supports relative to the other, a hydraulic control circuit for said motor, including a decelerator valve member and a reversing valve member, piston and cylinder means for shifting said reversing valve member in opposite directions, a pilot valve operable by tne table for alternately connecting a source of fluid pressure to one of said piston and cylinder combinations, one of said connections including a throttle valve and a hydraulic resistance connected in parallel to one of said cylinders, means controlled by the shitable valve for alternately establishing said connections whereby the throttle valve will control the rate of the rst part of said shifting movement, andthe hydraulic resistance will control the rate of the remainder of said shifting movement.

5. In a machine tool having relatively movable tool and work supports and a uid operable motor for controlling reciprocation of one of said supports relative to the other, the combination of a hydrauliccontrol circuit for said motor including a hydraulically actuable reversing valve for the motor circuit, a pilot valve for determining the coupling of hydraulic medium with the reversing valve for effecting alternate directional movements thereof, a pair of resistance elements intervening the pilot valve and one end of the reversing valve, means in the reversing valve for sequentially coupling the resistance elements in controlling relation to the said valve to determine successive rates of movement thereof during unidirectional shifting under influence of the pilot valve circuit, an additional plurality of resistance elements, conduit means potentially coupling said additional resistance elements in serial relation between the pilot valve and said end of the reversing valve, and means for establishing alternate couplings of the sets of resistance elements with one end of the reversing valve for determination of its respective successive rates of movement in opposite directions.

6. In a machine tool having relatively movable tool and work supports and a fluid operable moto-1- for controlling reciprocation of one of said supports relative to the other, the combination of a hydraulic control circuit for said motor including a hydraulically actuable reversing valve for the motor circuit, a pilot valve for determining the coupling of hydraulic medium with the reversing valve for eiecting alternate directional movements thereof, a pair of resistance elements intervening the pilot valve and one end of the reversing valve, means in the reversing valve for sequentially coupling the resistance elements in controlling relation to the said valve to determine successive rates of movement thereof during unidirectional shifting under influence of the pilot valve circuit, an additional plurality of resistance elements, conduit means potentially coupling said additional resistance elements in serial relation between the pilot valve and said end of the reversing valve, means for establishing alternate couplings of the sets of resistance elements with one end of the reversing valve for determination of its respective successive rates of movement in opposite directions, and means individual to each set of resistances for varying one of said resistances whereby the rate of movement of the reversing valve during the effectiveness of said individual resistance with respect thereto may be adjustably determined. p

7. In a machine tool having a movable support, a uid operable motor for controlling reciprocation of the support and a hydraulic operating circuit including a source of hydraulic pressure medium for activation of the motor, means for controlling the action of the medium with respect tothe motor including a valve housing in the hydraulic circuit having a plurality of pressure inlet and outlet ports formed therein, a reversing sleeve Valverslidably mounted within the casing having conduit portions respectively communieating with the several ports of the casing, a cylindrical valve spindle slidably mounted Within the sleeve and having cannelures selectively positionable for variable coupling of the conduits in the sleeve, means operable by the motor for determining the position of the valve Mspindle and thus of. the cannelures with respect to the conduits in the sleeve, and additional means for eff fecting movement of the sleeve with respect to the spindle to vary the coupling of the conduits in the sleeve with the cannelures for a prescribed positioning of the valve spindle.

8. In a machine tool having a movable support, a fluidl operable motor for controlling reciprocation of the support and a hydraulic operating circuit including a source of hydraulic pressure medium i'oractivation or" the motor, means for controlling the action of the medium with respect to the motor including a valve housing in the hydraulic circuit having a plurality of pressure inlet and'outlet ports formed therein, a reversing sleeve valve slidably mounted within the casing having conduit portions respectively communi,- cating with the several ports of the casing, a cylindrical valve spindle slidably mounted within the sleeve and having cannelures selectively positionable for variable coupling of the conduits in the sleeve, means operable by the motor` for determining the position of the valve spindle and thus of the cannelures with respect to the conduits in the sleeve, additional means for efecting movement of the sleeve with respect to the spindle to vary the coupling of the conduits in the sleeve with the cannelures for a prescribed positioning of the valve spindle, and a plurality of rate determining devices adapted to control the rate of adjusting movement of the sleeve, the sleevehaving portions effective during movement thereof to determine the action of the rate control devices with respect thereto.

9. In a machine tool of the character described, the combination with a movable support and a hydraulic motor for controlling the rate and direction of support movement, of means actuable by movement of the support for ycontrolling the motor including a pilot valve and a stop valve each mechanically actuable by the support, said stop valve having variably positionable flow controlling portions, a source of hydraulic pressure medium, a reversing valve having ports variably positionable for serial cooperation with the flow controlling portions of the stop valve, and conduits serially coupling the source, the reversing and stop valves with the motor whereby the relative positions of the stop and reversing valves will be determinative of the directional operation of the motor, piston means for actuating the revel-sing valve, and auxiliary pilot conduits inter-r.

connecting the pilot valve, the source of pressure and said piston means whereby support determined positioning of the pilot valve will cause the hydraulic pressure to act on the reversing valve for .effecting a reverse hydraulic positioning thereof.

10. In a machine tool of the character described, the combination with a movable support and a hydraulic motor for controlling the rate and direction of support movement, of means actuable by movement of the support for controlling the motor including a pilot valve and a stop valve each mechanically actuable by the support, said stop valve having variably positionable flow controlling portions, a source of hydraulic pressure medium, a reversing valve having ports variably positionable for serial cooperation with the flow controlling portions of the stop valve, and conduits serially coupling the source, the reversing and stop valves with the motor whereby the relative positions of the stop and reversing valves will be determinative of the directional operation of the motor, piston means for actuating the reversing Valve, auxiliary pilot conduits interconnecting the pilot valve, the source of pressure and said piston means whereby support determined positioning of the pilot valve will cause the hydraulic pressure to act on the reversing valve for effecting a reverse hydraulic positioning thereof, a pair of hydraulic resistances interposed in the pilot circuit between thepilot valve and the actuating pistons for the reversingl valve, and means for sequentially coupling said resistances with the reversing valve during unidirectional movement thereof whereby the time of movement of the reversing valve through tarry and reverse accelerating positions may be controlled.

11. In a machine tool of the character def scribed, the combination with a movable support and a hydraulic motor for controlling the rate and direction of support movement, of means actuable by movement of the support for controlling the motor including a pilot valve and a stop valve each mechanically actuable by the support, said stop valve having variably positionable flow controlling portions, a source of hydraulic pressure medium, a reversing valve having ports variably positionable for serial cooperation with the now controlling portions of the stop valve, and conduits serially coupling the source, the reversing and stop valves with the motor whereby the relative positions of the stop and reversing valves will be determinative of the directional operation of the motor, piston means for actuating the reversing valve, auxiliary pilot conduits interconnecting the pilot valve, the source of pressure and said piston means whereby support determined positioning of the pilot valve will cause the hydraulic pressure to act on the reversing Valve for effecting a reverse hydraulic positioning thereof, a pair of hydraulic resistances interposed in the pilot circuit between the pilot valve and the actuating pistons for the reversing valve, means for sequentially coupling said resistances with the reversing valve during unidirectional movement thereof whereby the time of movement of the reversing valve through tarry and reverse accelerating positions may be controlled, additional hydraulic resistances, and means for effecting sequential operative coupling of said additional hydraulic resistances' sequentially in controlling relation to the reversing'valve upon opposite actuation of the pilot valve whereby to control the period of tarry and acceleration of the motor and support in an opposite direction.

CHARLES HERFURTH. RAYMOND D. W ORTENDYKE. 

